Final answer:
All that needed to use the CRISPR/Cas9 system to replace a mutation with a normal gene sequence are 1) A linear double-stranded DNA which contains the normal sequence of the gene and 2) A guide RNA that is complementary to the mutated sequence of the gene.
Step-by-step explanation:
In order to use the CRISPR/Cas9 system to replace a mutation with a normal gene sequence, a linear double-stranded DNA which contains the normal sequence of the gene, this is required to provide the correct gene sequence that will replace the mutated sequence.
The guide RNA will direct the CRISPR/Cas9 system to the specific location of the mutated sequence in the gene.The CRISPR/Cas9 system works by using the guide RNA to target the specific mutated sequence in the gene. The Cas9 protein then cuts the DNA at the targeted location, allowing for DNA repair mechanisms to insert the correct gene sequence, effectively replacing the mutation.
This technology has revolutionized gene editing and has the potential for various applications such as targeted gene therapies and genetic modifications of organisms. So therefore the correct answer are 1) A linear double-stranded DNA which contains the normal sequence of the gene and 2) A guide RNA that is complementary to the mutated sequence of the gene.